The present invention relates to a new and improved method of, an apparatus for, copying images or pictures from a transparent image carrier on to a light sensitive copy carrier, typically light-sensitive paper.
Generally speaking, in accordance with the method of the invention a light beam emanating from a light source is projected through the transparent image carrier and an objective on to the light sensitive copy carrier located at the focal point of the objective. Both the part of the image carrier and the part of the copy carrier, impinged during the copying process by the light beam, are located upon co-axial cylinder segments and are moved. The objective is stationarily arranged at a common axis of the cylinder segments.
As to the apparatus for performance of the aforesaid method the same contains two co-axial cylinders at whose common axis of rotation there is located an objective. The image carrier and copy carrier bear at least partially upon segments of the cylinders, and both of these cylinders are rotatable. A light source is arranged so that it projects a light beam through the image carrier and the objective on to the copy carrier.
For the purpose of rationally copying, particularly photo negatives in strip-shaped configuration on to photo sensitive paper, there are required extremely rapidly operating copying processes and copying equipment. Such processes and equipment have been known for quite some time as have also been various magnification and scanning techniques of the article which is to be copied in the copying device.
According to a number of different heretofore known methods and apparatuses, such as for instance described in Swiss Pat. No. 514,864 of Xerox Corporation, the stationary image or picture carrier is projected upon a moved copy carrier by means of a moved light source and moved objective, wherein at times the copy carrier can be strip-shaped as, for instance, disclosed in Swiss Pat. No. 473,397 of General Aniline & Film Corporation.
Furthermore, apparatuses have become known to the art from Swiss Pat. No. 527,452 of International Business Machines Corporation wherein the image carrier located upon a cylinder segment is projected by means of a light beam from a stationary light source by means of an at least partially rotating mirror and an objective on to a moved copy carrier.
Moreover, there are also known quite complex and complicated methods and apparatuses wherein the image is projected from an image carrier, by means of a completely movable mirror system, on to a movable copy carrier, as such has for instance been disclosed in Swiss Pat. No. 503,292 of International Business Machines Corporation.
Additionally, apparatuses are known from German Patent Publication No. 2,619,447 of Rank Xerox Limited, wherein an image carrier guided over mirrors and an objective, by means of a cylindrical segment-shaped transparent support, is likewise projected on to a moved copy carrier.
Also in Swiss Pat. No. 601,835 there is disclosed an apparatus for projecting a film picture or image. Here, the image carrier and the copy carrier are arranged upon co-axial cylinder segments and the image is projected on to the copy carrier bearing upon the inner cylinder, and, if necessary, the light beam is guided by means of a likewise co-axial cylinder segment-shaped mirror and an objective located at the common axis.
Additionally, there is known from European Patent Application No. 78300105.0, published under publication No. 0000286 of Western Electric Company Incl., a method and apparatus wherein the image carrier and copy carrier are each respectively located upon a rotating cylinder. The image is continuously projected in a strip-shaped fashion from the image carrier on to the copy carrier by means of a fixed mirror and objective system arranged between the cylinders.
Each of the presently known copying methods and all of the equipment serving for the practice thereof possess disadvantages which, in part, appreciably effect the copying speed and complexity of the required equipment controls. Furthermore, as a rule, they also require complicated constructions of the copying equipment.
Thus, for instance, the control of the movement of a light source, but equally the control of the movement of an objective, as a function of the movement of the image carrier or copy carrier is technically extremely complicated. Even more complicated is the control of the movement of the mirrors or reflectors which must deflect the projection beam from the image carrier on to the copy carrier. Additionally, the projection of a flat or planar image upon a curved copy surface constitutes an optically complicated task. Moreover, each stepwise functioning method or each discontinuous work step automatically negatively affects the operating speed of the method and the equipment. Furthermore, such procedures require additional and complicated controls and mechanisms.